In recent years, the incidence of various kinds of adult diseases is rapidly increasing due to improvement of the living environment and changes in dietary life of modern people, and the incidence of chronic diseases such as cancer, atherosclerosis, stroke, diabetes, hypertension, etc., is significantly increasing due to excessive nutrition or unbalanced diet. In particular, cancer has been the leading cause of death from the past to the present. Major methods for treating cancer include drug therapy, surgery, and radiation therapy, etc., and various other methods are also being attempted. However, drug therapy inevitably causes side effects because it requires a high dose of an anticancer agent so as to provide an appropriate accumulation level of the anticancer agent in the lesions.
Meanwhile, as the inhibition of intercellular signaling through gap junction channels is recognized as an important biochemical marker of cancer development, those materials which inhibit the process are being recognized as materials having effects of preventing and inhibiting cancer. As an anticancer agent exhibiting an effect of inhibiting the intercellular signaling, doxorubicin (i.e., a type of quinone-based compounds) was developed. Doxorubicin is known to have anticancer activity against solid tumors such as breast cancer, ovarian cancer, liver cancer, etc., and thus it may also be used generally for the treatment of other cancers. It is known that when the dose of doxorubicin is decreased for safe treatment, the efficiency of anticancer treatment decreases significantly, whereas when the dose of doxorubicin is increased for effective cancer treatment, it causes a side effect of inhibiting intercellular signaling.
Various studies are underway to overcome side effects of anticancer agents. For example, Korean Patent No. 553266 discloses an anticancer composition, which contains quercetin, which has the effects of preventing the side effects of intercellular signaling caused by doxorubicin and increasing the inhibition of the activity of matrix metalloproteinase, along with doxorubicin, and use thereof. Korean Patent No. 633452 discloses an anticancer agent containing a cocoa extract capable of recovering intercellular signaling through gap junctions by compensating the side effect of doxorubicin (i.e., inhibition of intercellular signaling through gap junctions). However, the above techniques have a disadvantage in that they can only suppress the side effect of doxorubicin itself and cannot solve the side effect caused by the administration of an excessive dose of doxorubicin. Since most side effects of anticancer agents are known to be caused by the administration of an excessive dose of the agents for improving their therapeutic effects, continuous efforts are being made to develop methods that can exhibit the same level of therapeutic effects even after treatment with a small amount of the anticancer agents.